Beverages made with mushrooms are becoming a booming market, according to industry watchers. Products include teas, powdered lemonade mixes, broth, and protein shakes. Their growing popularity is mainly due to people searching for alternatives to animal-based nutrition. Mushrooms are fat-free, low in calories, and rich in protein, fiber, and many essential vitamins and minerals. The king of the mushroom market right now is a variety known as reishi (left). Sales of reishi-based foods are up 91 percent for the 52 weeks ending September 4. But sales growth is also impressive for chaga (up 46 percent), cordycep (up 19 percent) and shiitake (up 26 percent).